Moreover, muscle hypertrophy following chronic clenbuterol treatment increases the isometric force in fast-twitch skeletal muscle. Our study confirms these previous results. The absolute force of EDL muscle was increased following clenbuterol treatment, while the specific force was not different compared to controls, suggesting that the strength improvement was only due to the increased skeletal muscle mass. Analysis of representative recording of the decrease in EDL tension during the Cyclic Pifithrin-alpha hydrobromide fatigue protocol highlighted that the initial tension was higher and appeared earlier in clenbuterol-treated EDL muscles than in untreated controls, in accordance with the PD-407824 increase in muscle mass and the phenotypic shift to a faster contractile profile. Fatigability of EDL muscles from clenbuterol-treated animals was nevertheless increased, as the peak tetanic force fell more quickly in clenbuterol-treated EDL muscles than in controls, and Tlim, used as an index of resistance to fatigue, was significantly reduced. This last result confirmed that clenbuterol treatment negatively affects muscle endurance, in agreement with the phenotypic remodeling. Dengue virus infection may display either benign acute febrile illness or severe disease such as dengue hemorrhagic fever/ dengue shock syndrome. Over the last 31 years, Brazil has suffered successive outbreaks of dengue. The incidence of dengue continues to increase, and in the last decade 700,000 cases are reported per year. The mean age of severe dengue patients is decreasing. A high proportion of children are increasingly affected with severe disease. In recent years, dengue outbreaks have displayed many atypical cases such as myocarditis, hepatitis, meningoencephalitis and acute kidney failure. Fatality rates have also increased. In Manaus, the capital city of the Amazonas state, circulation of the four DENV serotypes was observed during the 2011 outbreak and is the only city to date to report co-circulation of all four DENV serotypes simultaneously in Brazil, providing a clear evidence of dengue hyperendemicity. The occurrence of severe forms of dengue is commonly related to secondary infections leading to antibody dependent enhancement of DENV infection in macrophages.